In plant taxonomy, ginseng is a perennial plant belonging to the genus Panax of the family Araliaceae, and about 11 species of ginseng are known so far. Among them, Panax Ginseng C. A. Meyer is typically known to have excellent medicinal effects. The term “ginseng” is used in the broadest sense to include all fresh ginseng, white ginseng, red ginseng, wild mountain ginseng, woods grown ginseng, tail ginseng, cultured ginseng and the like. Ginseng is a natural material that has been used as a highly valuable medicinal drug in Chinese medicine, and the medicinal effects of ginseng are found in many medical books. Although ginseng has been used for a long period of time, the scientific elucidation of effects of ginseng by clinical studies is still insufficient. Nevertheless, even after modern medicine was introduced, ginseng did not lose its popularity and ranks first among health functional foods. This is thought to be because ginseng is a crude drug that exhibits clinically proven medicinal effects, has fewer side effects and is highly safe. The major functional components of ginseng are ginseng saponins which are distinguished from the saponins of other plants and called ginsenosides. The ginseng saponins have pharmacological effects, including anticancer, anti-allergy, anti-inflammation, central nervous inhibition, relaxation, pain relief, memory improvement, liver injury recovery, protein and lipid synthesis stimulation, anti-diabetes, anti-stress, antioxidant substance promotion stimulation, immune regulation, platelet aggregation inhibition and anti-aging effects.
Saponins are classified into a variety of ginsenosides according to the kind and number of sugars (glucose, arabinose, and rhamnose) bound to a substituent. These saponins are hardly degraded by digestive enzymes in vivo after oral intake (Hasegawa, H. et al., Microbial Ecololgy in Health and Disease, 12, 85-91, 2000) and absorbed after degradation into 20(S)—O-β-protopanaxadiol 20-O-β-D-glucopyranoside, 20(S)-protopanaxadiol and 20(S)-protopanaxatriol by intestinal microorganisms (Hasegawa, H. et al., Planta Medica, 62, 453-457, 1996). However, the absorption of saponins differs between individuals, because intestinal microorganisms significantly differ between individuals.
Meanwhile, among the main components of ginseng, saponins such as ginsenosides Rb1, Rb2 and Rc are known to exhibit the pharmacological effects of ginseng. However, it is known that the components of ginseng, which are substantially involved in anticancer effects, inhibition of cancer cell metastasis, or anti-allergy effects, are compound K (comp K), and saponins of ginsenosides Rb1, Rb2 and R3, which are contained in very small amounts in ginseng. Ginsenoside Rh2 and compound K, which comprise a glucose molecule bound to a substituent, have excellent anticancer, anti-allergic and anti-inflammatory effects and, at the same time, show high intestinal adsorption and absorption rates, because the number of sugar chain bonds therein is not large so that they have low hydrophilicity. Thus, in order to use the anticancer, anti-allergic and immune-enhancing effects of ginseng, it is preferable to increase the contents of compound K and ginsenosides Rh2, Rh1 and Rg3, which are not contained or are contained in very small amounts in ginseng.
Accordingly, in recent years, in order to increase the contents and facilitate the in vivo absorption of ginseng active ingredients (ginsenosides) which are not contained or are contained in very small amounts, various methods have been attempted, including a method of fermenting ginseng using microorganisms, a method of treating ginseng with enzymes, and a method of hydrolyzing ginseng with acid. For example, Korean Patent Application No. 2000-58997 discloses a method of making absorbable, acid-saccharified ginseng using sulfuric acid or hydrochloric acid, and Korean Patent Laid-Open Publication No. 2003-87250 discloses a method of making processed ginseng having increased contents of ginseng active ingredients and containing red ginseng-specific ginsenosides using ultrahigh pressure. Further, Korean Patent Laid-Open Publication No. 2006-1834 discloses a method of preparing fermented ginseng or fermented red ginseng, comprising a step of inoculating ginseng or red ginseng with Kimchi lactic acid bacteria and treating the inoculated ginseng or red ginseng with acid, and Korean Patent Laid-Open Publication No. 2003-61756 discloses a method for preparing a fermented ginseng solution having excellent functional and sensory properties, the method comprising fermenting ginseng with Aspergillus and degrading the fermented ginseng with amylase and protease. In addition, Korean Patent Laid-Open Publication No. 2006-74970 discloses a fermented ginseng comprising a substance obtained by degrading glycosides in ginseng with Lactobacillus casei strain Hasegawa, and Korean Patent Laid-Open Publication No. 1998-40224 discloses a fermented ginseng comprising degraded saponin products obtained by fermenting ginseng with various Lactobacillus strains.